There is growing interest in the manufacture of ethylene from renewable sources. This trend is motivated by concerns about global warming and the uncertainty about prices of petroleum feedstock. As a result, leading manufacturers of ethylene are turning to ethanol as a raw material. The ethanol may be supplied by the fermentation of sugar from either sugar cane or corn syrup. The chemistry for producing ethylene from ethanol is well known. It is straightforward in concept, having been the subject of much academic research. Ethylene is formed by the dehydration of ethanol in the vapor phase reaction when the alcohol is passed over a catalyst of gamma aluminum oxide at a temperature in the range of 348° to 428° C.
The commercial application of this technology, however, presents certain problems. The catalyst life is limited. Byproducts are formed, including such impurities as heavy residues, as well as light ends. Furthermore, an inherent disadvantage of the chemistry is the coproduction of ether, which must be recovered and recycled in the process.
For these and other reasons, there is an incentive to develop new technology for the production of ethylene from ethanol. Thus, it is a goal of the present disclosure to provide a process that is efficient, robust and versatile in its use. These and other advantages, features, and characteristics of the process of the present disclosure will become apparent from the following description and the FIGURE that is included.